A rust spot with salt and paint
blisters, what a nice sight!

The smiling lisps of salt on rust

U.S. consumers, businesses, and government
organizations own more than 200 million registered motor vehicles. Assuming
the average value of an automobile is $5,000, the total investment Americans
have made in motor vehicles can be estimated at $1 trillion. Since the
1980s, car manufacturers have increased the corrosion-resistance of vehicles
by using corrosion-resistant materials, employing better manufacturing
processes, and designing corrosion-resistant vehicles. Although significant
progress has been made, further improvement can be achieved in corrosion
resistance of individual components. The total annual direct cost of
corrosion is estimated at $23.4 billion, which is broken down into the
following three components: (1) increased manufacturing costs due to
corrosion engineering and the use of corrosion-resistant materials ($2.56
billion per year), (2) repairs and maintenance necessitated by corrosion
($6.45 billion per year), and (3) corrosion-related depreciation of vehicles
($14.46 billion per year). (reference)